MTB alignment. Code, tests, application

modules/photo/include/opencv2/photo.hpp

@@ -94,12 +94,16 @@ CV_EXPORTS_W void fastNlMeansDenoisingColoredMulti( InputArrayOfArrays srcImgs,
                                                     float h = 3, float hColor = 3,
                                                     int templateWindowSize = 7, int searchWindowSize = 21);
 
-CV_EXPORTS_W void makeHDR(InputArrayOfArrays srcImgs, const std::vector<float>& exp_times, OutputArray dst);
+CV_EXPORTS_W void makeHDR(InputArrayOfArrays srcImgs, const std::vector<float>& exp_times, OutputArray dst, bool align = false);
 
 CV_EXPORTS_W void tonemap(InputArray src, OutputArray dst, tonemap_algorithms algorithm, 
 	                      const std::vector<float>& params = std::vector<float>());
 
-CV_EXPORTS_W void exposureFusion(InputArrayOfArrays srcImgs, OutputArray dst, float wc = 1, float ws = 1, float we = 0);
+CV_EXPORTS_W void exposureFusion(InputArrayOfArrays srcImgs, OutputArray dst, bool align = false, float wc = 1, float ws = 1, float we = 0);
+
+CV_EXPORTS_W void shiftMat(InputArray src, Point shift, OutputArray dst);
+
+CV_EXPORTS_W Point getExpShift(InputArray img0, InputArray img1, int max_bits = 6, int exclude_range = 4);
 } // cv
 
 #endif

modules/photo/src/hdr_fusion.cpp

@@ -85,7 +85,27 @@ static void checkImages(std::vector<Mat>& images, bool hdr, const std::vector<fl
 	}
 }
 
-void makeHDR(InputArrayOfArrays _images, const std::vector<float>& _exp_times, OutputArray _dst)
+static void alignImages(std::vector<Mat>& src, std::vector<Mat>& dst)
+{
+	dst.resize(src.size());
+
+	size_t pivot = src.size() / 2;
+	dst[pivot] = src[pivot];
+	Mat gray_base;
+	cvtColor(src[pivot], gray_base, COLOR_RGB2GRAY);
+
+	for(size_t i = 0; i < src.size(); i++) {
+		if(i == pivot) {
+			continue;
+		}
+		Mat gray;
+		cvtColor(src[i], gray, COLOR_RGB2GRAY);
+		Point shift = getExpShift(gray_base, gray);
+		shiftMat(src[i], shift, dst[i]);
+	}
+}
+
+void makeHDR(InputArrayOfArrays _images, const std::vector<float>& _exp_times, OutputArray _dst, bool align)
 {
 	std::vector<Mat> images;
     _images.getMatVector(images);
@@ -93,6 +113,11 @@ void makeHDR(InputArrayOfArrays _images, const std::vector<float>& _exp_times, O
 	_dst.create(images[0].size(), CV_32FC3);
 	Mat result = _dst.getMat();
 
+	if(align) {
+		std::vector<Mat> new_images;
+		alignImages(images, new_images);
+		images = new_images;
+	}
 	std::vector<float> exp_times(_exp_times.size());
 	for(size_t i = 0; i < exp_times.size(); i++) {
 		exp_times[i] = log(_exp_times[i]);
@@ -128,12 +153,17 @@ void makeHDR(InputArrayOfArrays _images, const std::vector<float>& _exp_times, O
 	result = result / max;
 }
 
-void exposureFusion(InputArrayOfArrays _images, OutputArray _dst, float wc, float ws, float we)
+void exposureFusion(InputArrayOfArrays _images, OutputArray _dst, bool align, float wc, float ws, float we)
 {
 	std::vector<Mat> images;
     _images.getMatVector(images);
 	checkImages(images, false);
 
+	if(align) {
+		std::vector<Mat> new_images;
+		alignImages(images, new_images);
+		images = new_images;
+	}
 	std::vector<Mat> weights(images.size());
 	Mat weight_sum = Mat::zeros(images[0].size(), CV_32FC1);
 	for(size_t im = 0; im < images.size(); im++) {

modules/photo/test/test_hdr.cpp

@@ -118,3 +118,26 @@ TEST(Photo_Tonemap, regression)
 		ASSERT_FALSE(max > 0);
 	}
 }
+
+TEST(Photo_Align, regression)
+{
+	const int TESTS_COUNT = 100;
+	string folder = string(cvtest::TS::ptr()->get_data_path()) + "hdr/";
+	
+	string file_name = folder + "grand_canal_1_45.jpg";
+	Mat img = imread(file_name);
+	ASSERT_FALSE(img.empty()) << "Could not load input image " << file_name;
+	cvtColor(img, img, COLOR_RGB2GRAY);
+
+	int max_bits = 6;
+	int max_shift = 64;
+	srand(time(0));
+
+	for(int i = 0; i < TESTS_COUNT; i++) {
+		Point shift(rand() % max_shift, rand() % max_shift);
+		Mat res;
+		shiftMat(img, shift, res);
+		Point calc = getExpShift(img, res, max_bits);
+		ASSERT_TRUE(calc == -shift);
+	}
+}
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